IB Biology Quiz: Technology
11 questions · exam conditions
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TechnologyQuestion 1 of 11

In the Hershey-Chase experiment, bacteriophages were grown in two separate media: one with radioactive sulfur (³⁵S) and another with radioactive phosphorus (³²P). What was the critical technological rationale for selecting these specific isotopes to trace the genetic material?

³²P is incorporated into the phosphate backbone of DNA, while ³⁵S is found in the amino acids methionine and cysteine within proteins.
³⁵S is incorporated into the nitrogenous bases of DNA, while ³²P is incorporated into the R-groups of all 20 amino acids.
³²P has a shorter half-life for more precise measurements, while ³⁵S provides a stronger radioactive signal for easier detection.
³⁵S labels the carbohydrate capsid of the virus, while ³²P labels the lipid components of the tail fibers.
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IB Biology Quiz

IB Biology Quiz: Technology

Practice Technology in IB Biology with focused quiz questions that help you check what you know, review explanations, and build confidence with test-style prompts.

What this quiz covers

This quiz focuses on Technology, giving you a quick way to practice the rules, question types, and explanations that matter most for IB Biology.

How to use this quiz

Try each quiz question before looking at the correct answer. Use the explanations to review missed ideas, then come back to similar questions until the pattern feels familiar.

All questions

Question 1

In the Hershey-Chase experiment, bacteriophages were grown in two separate media: one with radioactive sulfur (³⁵S) and another with radioactive phosphorus (³²P). What was the critical technological rationale for selecting these specific isotopes to trace the genetic material?

  1. ³²P is incorporated into the phosphate backbone of DNA, while ³⁵S is found in the amino acids methionine and cysteine within proteins. (correct answer)
  2. ³⁵S is incorporated into the nitrogenous bases of DNA, while ³²P is incorporated into the R-groups of all 20 amino acids.
  3. ³²P has a shorter half-life for more precise measurements, while ³⁵S provides a stronger radioactive signal for easier detection.
  4. ³⁵S labels the carbohydrate capsid of the virus, while ³²P labels the lipid components of the tail fibers.
Explanation: The design of the experiment relied on the unique elemental composition of DNA and proteins. DNA contains phosphorus in its sugar-phosphate backbone but lacks sulfur. Proteins, conversely, lack phosphorus but contain sulfur in some amino acids (methionine and cysteine). This allowed Hershey and Chase to selectively label and trace the DNA and protein coat of the virus separately.

Question 2

Hybridoma technology for producing monoclonal antibodies involves fusing antibody-producing plasma cells with myeloma (cancer) cells. What is the primary technological advantage conferred by the myeloma cell in the resulting hybridoma?

  1. It provides the specific antigen required to stimulate the plasma cell to produce antibodies.
  2. It ensures the resulting hybridoma cell can evade the host's immune system when used therapeutically.
  3. It provides the machinery for protein synthesis, such as ribosomes and tRNA, which plasma cells lack.
  4. It confers the property of unlimited cell division, allowing for sustained antibody production in culture. (correct answer)
Explanation: Plasma cells are specialized to produce a single type of antibody but have a limited lifespan. Myeloma cells are cancerous and are effectively immortal, meaning they can divide indefinitely in culture. Fusing the two creates a hybridoma cell that has both desired properties: it produces the specific antibody from the plasma cell and can be cultured long-term due to the immortality conferred by the myeloma cell.

Question 3

A researcher is using cell culture technology to grow human skin cells in a laboratory. The cells are provided with a complex medium containing glucose, amino acids, vitamins, and salts in a buffered, isotonic solution. To stimulate the cells to progress through the cell cycle and undergo mitosis, which additional substance is typically required?

  1. Mitochondria to provide ATP for division.
  2. Growth factors from serum. (correct answer)
  3. DNA polymerase for replication.
  4. Ribosomes for protein synthesis.
Explanation: Most mammalian cells require external signals in the form of growth factors to progress through the cell cycle. These are typically supplied by adding serum (like fetal bovine serum) to the culture medium. Growth factors bind to cell surface receptors and trigger signaling pathways that allow cells to pass cell cycle checkpoints and enter mitosis.

Question 4

A cell biologist can easily visualize a mitochondrion using a standard light microscope but cannot resolve an individual ribosome within the same cell. What is the fundamental technological limitation of the light microscope that explains this difference?

  1. The wavelength of visible light is longer than the diameter of a ribosome, preventing its resolution. (correct answer)
  2. The magnification of even the best light microscope is insufficient to enlarge a ribosome to a visible size.
  3. The stains used for light microscopy bind to mitochondrial membranes but not to ribosomes.
  4. The glass used to make microscope lenses absorbs the light reflected from objects as small as ribosomes.
Explanation: The ability of a microscope to distinguish two close objects as separate is called resolution. The resolution is fundamentally limited by the wavelength of the illumination source. Ribosomes (~25 nm) are smaller than the shortest wavelength of visible light (~400 nm). Consequently, light waves diffract around the ribosome rather than resolving its structure. Electron microscopes achieve higher resolution by using electrons, which have a much shorter wavelength.

Question 5

The production of transgenic bacteria that can synthesize human insulin relies on creating a recombinant plasmid. A critical step in this technology is to cut both the human insulin gene and the bacterial plasmid with the same restriction enzyme. What is the direct consequence of this step?

  1. It ensures the plasmid and the human gene are of a similar size for efficient bacterial uptake.
  2. It prevents the bacterium's own defense mechanisms from destroying the foreign human DNA.
  3. It adds a promoter sequence to the human gene so that it can be transcribed by the bacterium.
  4. It generates compatible 'sticky ends' on both DNA fragments, allowing them to anneal. (correct answer)
Explanation: Most restriction enzymes make staggered cuts in the DNA, creating short, single-stranded overhangs known as 'sticky ends'. By using the same enzyme to cut both the plasmid vector and the gene insert, their sticky ends will be complementary. This allows the insert to anneal (base-pair) with the plasmid, holding it in place so that DNA ligase can form permanent phosphodiester bonds to create the recombinant molecule.

Question 6

When designing a viral vector for use in human gene therapy, a critical technological modification is the removal of the virus's own replication and pathogenesis genes. What is the primary safety reason for this modification?

  1. To prevent the virus from causing disease in the patient or from reproducing uncontrollably. (correct answer)
  2. To ensure the therapeutic gene is inserted into a specific, safe location in the host's chromosomes.
  3. To create physical space within the viral capsid to accommodate the large therapeutic human gene.
  4. To allow the viral vector to infect a wider range of human cell types than the original virus.
Explanation: The main goal is to use the virus as a delivery vehicle (a vector) for the therapeutic gene, harnessing its natural ability to enter cells. However, the original virus is pathogenic and can replicate, which would cause disease in the patient. By removing the genes responsible for these functions, the vector is 'gutted' and rendered replication-incompetent and non-pathogenic, making it a safe tool for gene delivery.

Question 7

Ecologists use sealed glass mesocosms to investigate the resilience of small ecosystems. Despite allowing for the control of variables, this technology has inherent limitations. Which of the following represents a significant limitation of using a mesocosm to model a large, natural lake ecosystem?

  1. The fundamental principles of energy flow and nutrient cycling do not apply in small, artificial systems.
  2. It is impossible to establish a stable food web with more than two trophic levels in a sealed container.
  3. The small volume prevents the establishment of realistic nutrient concentrations and thermal stratification. (correct answer)
  4. Abiotic factors such as light intensity and temperature cannot be manipulated in a controlled manner.
Explanation: Large ecosystems like lakes have complex physical properties, such as thermal stratification (layers of different temperatures) and vast nutrient sinks and sources, that are impossible to replicate at the small scale of a mesocosm. The edge effects (influence of the container walls) and the lack of volume and depth prevent the model from accurately representing these large-scale physical and chemical processes.

Question 8

A genetic engineer is designing a CRISPR-Cas9 system to correct a specific point mutation in a target gene. The remarkable specificity of this gene-editing technology primarily relies on which of its components?

  1. The palindromic DNA sequence of the target site, which is recognized directly by the Cas9 protein.
  2. The nucleotide sequence of the guide RNA (gRNA), which is complementary to the target DNA sequence. (correct answer)
  3. The catalytic domains of the Cas9 protein, which have an innate binding affinity for the specific target gene.
  4. The protospacer adjacent motif (PAM) sequence, which is recognized by the gRNA to initiate binding.
Explanation: The CRISPR-Cas9 system's specificity comes from the guide RNA (gRNA). A portion of the gRNA is engineered to have a sequence that is complementary to the target DNA. This gRNA molecule guides the Cas9 enzyme to the precise location in the genome where the cut is to be made. The Cas9 protein itself does not have sequence-specificity for the target.

Question 9

Paper chromatography is a technology used to separate pigments from a plant extract. The separation into distinct bands of colour occurs because the different pigment molecules possess different...

  1. molecular masses, with heavier pigments moving more slowly up the paper.
  2. net electrical charges, causing differential attraction to the charged paper fibers.
  3. degrees of solubility in the solvent and adhesion to the stationary paper. (correct answer)
  4. absorption spectra, causing them to be pushed along by light at different rates.
Explanation: Paper chromatography is a form of partition chromatography. Separation depends on the differential partitioning of components between a stationary phase (the paper, which is polar) and a mobile phase (the solvent, which is typically non-polar). Pigments that are more soluble in the non-polar solvent and have weaker adhesion to the polar paper will travel further up the paper, resulting in separation.

Question 10

mRNA vaccines represent a different technology from traditional vaccines using inactivated viruses. What is the fundamental difference in how these two technologies initiate an immune response?

  1. Inactivated viruses are presented directly to B-cells, while mRNA vaccine antigens are presented to T-cells.
  2. Traditional vaccines introduce a foreign antigen, while mRNA vaccines cause the host's cells to produce the foreign antigen. (correct answer)
  3. mRNA vaccines introduce viral DNA into the host cell nucleus, triggering a long-term immune memory.
  4. Inactivated viruses stimulate only the innate immune system, whereas mRNA vaccines stimulate the adaptive system.
Explanation: The core technological difference lies in the source of the antigen. A traditional inactivated virus vaccine contains the actual viral proteins (antigens) which are introduced into the body directly. An mRNA vaccine contains the genetic instructions (mRNA) for a viral antigen. The host's own cells take up this mRNA and use their ribosomes to synthesize the foreign antigen. This self-produced antigen is then what stimulates the immune response.

Question 11

During the preparation of a human karyogram, cells are treated with a substance like colchicine that disrupts mitotic spindle formation. What is the direct technological purpose of this specific step?

  1. To induce chromosomal non-disjunction, thereby making genetic abnormalities more prominent.
  2. To cause the nuclear envelope to break down, releasing chromosomes for easier collection.
  3. To arrest the cells in metaphase, when chromosomes are maximally condensed and clearly visible. (correct answer)
  4. To selectively destroy all cells not currently undergoing mitosis, purifying the sample.
Explanation: For a karyogram, chromosomes must be clearly visible and distinguishable. They reach their most condensed and compact state during metaphase of mitosis. By disrupting the mitotic spindle, colchicine prevents the cell from progressing past metaphase into anaphase. This causes cells to accumulate at the metaphase stage, providing a large number of cells with chromosomes suitable for imaging and analysis.